Feasibility and results of subtype-oriented protocols in older adults and fit elderly patients with acute lymphoblastic leukemia: Results of three prospective parallel trials from the PETHEMA group.

ABSTRACT

BACKGROUND AND OBJECTIVE: The prognosis of acute lymphoblastic leukemia (ALL) is poor in older adults and elderly patients, and subtype-oriented prospective trials are scarce in these patients. We present the results of three prospective parallel subtype-oriented protocols in fit patients older than 55 years. PATIENTS AND METHODS: In 2008, three prospective phase II trials in patients older than 55 years were activated ALLOLD07 for Philadephia (Ph) chromosome-negative ALL, ALLOPH07 for Ph-positive ALL, and BURKIMAB08 for mature B-ALL. Early death (ED), complete remission (CR), disease-free survival (DFS), overall survival (OS) and toxicity were analyzed. RESULTS: 56, 53 and 21 patients from the ALLOLD07, ALLOPH07 and BURKIMAB08 trials, respectively, were evaluable. CR was 74%, 87% and 70%, with an ED rate of 13%, 11% and 15%, respectively. The medians of DFS were 8 and 38 months for ALLOLD07 and ALLOPH07 protocols, not being achieved in the BURKIMAB08 trial (p=0.001), and the median OS was 12, 37 and 25 months, respectively (p=0.030). Neutropenia, thrombocytopenia and infections were less frequent in the ALLOPH07 trial vs. ALLOLD07 and BURKIMAB trials, and renal toxicity and mucositis were more frequent in the BURKIMAB08 trial vs. the ALLOLD07 and ALLOPH07 trials. ECOG score and WBC count had prognostic significance for OS in ALLOPH07 and BURKIMAB08 trials, whereas no prognostic factors were identified in ALLOLD07 protocol. CONCLUSION: Subtype-oriented treatment had an impact in the outcome of older adults with ALL. The poorest outcome was observed in Ph-negative non-Mature B-cell ALL patients, for whom improvements in therapy are clearly needed.